#include<bits/stdc++.h>
const int maxn=1e6;
inline const void read(int &a)
{
    a=0;
    char c=getchar();
    while(c<'0'||c>'9')c=getchar();
    while(c>='0'&&c<='9')
    {
        a=(a<<1)+(a<<3)+c-'0';
        c=getchar();
    }
}
inline const void write(int a)
{
    if(a>=10)write(a/10);
    putchar(a%10+'0');
}
class SIDE
{
    public:
        int from,to,len,next;
        bool operator<(const SIDE&b)
        {
            if(len<b.len)return true;
            else return false;
        }
}s[maxn];
int n,ans=0,point[maxn],dis[maxn],son[maxn];
bool exist[maxn],wei[maxn];
inline const void add(int i)
{
    s[i].next=point[s[i].from];
    point[s[i].from]=i;
}
bool been[maxn];
void link_cut_tree(int p)
{
    been[p]=true;
    int side=point[p];
    while(side)
    {
        if(!been[s[side].to])
        {
            link_cut_tree(s[side].to);
            if(dis[s[side].to]+s[side].len>dis[p])
            {
                dis[p]=dis[s[side].to]+s[side].len;
                son[p]=s[side].to;
            }
        }
        side=s[side].next;
    }
}
void dfs(int p)
{
    if(wei[p])wei[son[p]]=true;
    been[p]=true;
    int side=point[p];
    while(side)
    {
        if(!been[s[side].to])
        {
            ans+=s[side].len*2;
            dfs(s[side].to);
            if(wei[s[side].to])ans-=s[side].len;
        }
        side=s[side].next;
    }
}
int main()
{
    memset(wei,false,sizeof(wei));
    memset(son,0,sizeof(son));
    memset(dis,0,sizeof(dis));
    memset(been,false,sizeof(been));
    memset(point,0,sizeof(point));
    read(n);
    for(int i=1;i<=n-1;i++)
    {
        read(s[i].from);read(s[i].to);read(s[i].len);
        add(i);
        s[i+n-1].from=s[i].to;s[i+n-1].to=s[i].from;
        s[i+n-1].len=s[i].len;exist[i+n-1]=exist[i];
        add(i+n-1);
    }
    link_cut_tree(1);
    memset(been,false,sizeof(been));
    wei[1]=true;
    dfs(1);
    write(ans);
    return 0;
}